What is integrative sports nutrition? – Ian Craig

If we truly want to nourish our athlete to full health and fitness, however, we need to delve deeper, much deeper. What happens, for example, when our active individual lacks adequate digestive fire to assimilate these well apportioned ‘fuels’, and in the process creates an inflammatory tone in his or her body? And how does our aspiring athlete cope when they are genetically not well suited to the diet that is prescribed by the sports nutritionist, which is based merely on the energetic needs of their sport?

As practitioners of sport and exercise, it is our duty to get to know and understand the health requirements of our active client in the context of the ecosystem within which they live. With that highly personalised knowledge, by deeply nourishing their physiological systems with wholesome foods and carefully selected supplements, we can start to rebuild and support their health and exercise resilience. By also reducing environmental toxicities, teaching them to manage stress, and balancing the training demands of our athlete, thereby lowering overall ‘life load’, it should help them to better tolerate demanding training regimes, and in the process, optimise recovery.

An integrative sports nutrition perspective

It is therefore no longer acceptable to work purely in a quantitative way. Our athlete clients should not be defined simply by the number of miles, watts, kilos, sets and reps in their training logs, and the grams of carbohydrates, fats, and proteins on their plate. Athletes are complex human beings who are actually under more physical pressure than regular individuals, and therefore require even more physiological support.

Integrative thinking, with the rapid evolution of integrative and functional medicine (1,2), has been applied in modern medical practices since the 1980s, but within traditional health practices for thousands of years. Likewise, many health-based nutritionists have now adopted a ‘functional practice’ by undertaking training in fields such as functional medicine and nutrigenomics. However, by and large, the sports nutrition fraternity still clings to the academic over-analyses of macronutrient needs.

That being said, after a landmark research study demonstrated that beetroot juice could extend time to exhaustion in cyclists (4), the floodgates of enquiry into food-based ingredients literally opened up into almost any fruit or vegetable extract imaginable. We need to extend these recent sports nutrition research interests further though. Rather than simply viewing food as ‘fuel’ or as potential ergogenic nutrients, integrative nutrition recognises that our day-to-day dietary choices have the power to nourish all of our mind-body systems. Gastrointestinal, immune, detoxification, musculoskeletal, neuroendocrine, bioenergetic, and mental-emotional health are all nourished by the food we eat, and integrate with one another to such a degree that their function is completely inter-dependant.

A good analogy to describe these integrative workings is to consider the old fashioned, mechanical watch – see Figure 1. Behind the face lies a collection of inter-connecting cogs of varying sizes, all of which interact interdependently in order to allow the watch to keep accurate time and thus function correctly. Ultimately the watch will only work seamlessly when each cog is ‘healthy’, interacting fluently with all other cogs, and synchronising the overall performance of the instrument within the particular environment it finds itself within. Food, alongside other positive lifestyle practices, possesses the power to do this in the context of human exercise physiology.

Figure 1 – Healthy interaction of body systems as represented by an old fashioned watch

We can also add another use of the word ‘integrative’ in the field of sport and exercise nutrition. Ideally, as practitioners, we need to be drawing together perspectives from different professional lines of enquiry – rather than staying in our comfort zone and reading the same journals. Kalman and Campbell from the International Society of Sports Nutrition aptly summed up that thought: “The integration of many different disciplines (physiology, metabolism, psychology, etc.) will become a minimum mandatory set of disciplines for any aspiring sports nutritionist (5)”. Likewise, this notion has been mirrored by Picard and McEwan from the field of psychosomatic research: “Historically, it has been noted that progress within individual fields of investigation can be hindered by a lack of understanding of the relationships across fields (6).” In other words, to be the best sport and exercise practitioner that you can be, read widely.

Gastrointestinal health – an example of integrative function

Gastrointestinal (GI) health forms an excellent working example of this integrative concept because it influences every single body system, plus our mind and cognitive function. To illustrate this vital organ system, I’ll share some gut-axis examples. The most researched is the gut-brain axis: it is understood that inflammation at the level of our gut is mirrored neurally and centrally, and conversely emotional upset, anxiety, depression, or neurotransmitter imbalance can greatly impact the GI function (e.g. 7,8).

The gut-mitochondrial axis is also now recognised, which steps us into the energetic demands of exercise. With the mind-blowing appreciation that mitochondria are descendants of bacteria (9), it appears that signals from the GI microbiota can greatly impact the mitochondrial respiratory chain and ATP production. Conversely, it’s been shown that the mitochondria coordinate many metabolic functions that are vital for the longevity of the microbiota, such as cellular respiration, fatty acid oxidation, and oxidative phosphorylation (10). This dynamic physiological understanding thankfully helps us to step away from the one-dimensional notion held by many scientists and practitioners that our mitochondria are simply energy factories used to turn substrates into ATP molecules.

We are now also in an exciting era of GI research within the fields of health and human performance. In addition to the gut-brain and gut-mitochondrial axis just mentioned, other acknowledged areas of research include the gut-muscle axis (e.g. 11,12), gut-lung axis (13), gut-immune axis (14), and the gut-thyroid axis (15).

Additionally, after more than two decades of GI observational studies in sport (16), recognising how athletes can be prone to GI symptoms, evolution of the microbiome research has sparked recent interest in GI health and microbial balance from a sporting context. A plethora of well written review papers, including one by the International Society of Sports Nutrition (7,17-19) have thankfully brought gastrointestinal awareness to the forefront. Our next step in this area is to educate practitioners about the powerful nutritional and lifestyle interventions that can positively support athletes’ GI function – strategies that have already been steeped in integrative health practice for many years.

The integrative sports nutrition performance pyramid

Cast your attention to the pyramid in Figure 2; it is a tiered representation of what I view as the important nutritional contributions to the performance of physically active individuals. The pyramid model includes and respects the sports nutrition paradigm of fuel required for physical performance alongside an integrative view of our body systems health, the quality of food sourced and prepared, and supplements that may further support the athlete’s performance goals.

Figure 2 – Integrative sports nutrition performance pyramid

Top layer: All too often, athletes start at the top layer, with questions like; “how much creatine do I need to boost hypertrophy”, “what’s the best dosage of beetroot juice to improve my cycling time trial performance”, “what is the ideal timing for sodium bicarbonate dosing before my 400m race”, and “is l-carnitine a proven fat burner?” These are all ergogenic questions; i.e. direct, scientifically tested, performance benefits of taking a certain supplement.

An athlete also has health-focussed supplements available to him or her. General choices might include vitamins, minerals, antioxidants, amino acids, and fish oils – the exact combination can be guided by the athlete’s health and training history, and perhaps even laboratory test results. Other possible supplements could involve specific support for their digestive processes, detoxification, endocrine system, immunity, bioenergetics, and musculoskeletal health.

Carefully-chosen good quality supplements should absolutely form part of an athlete’s nutrition strategy, but only once the preceding layers of the pyramid have been built.

Second layer: The classical quantitative sports nutrition model works very well here, when individual differences and training demands are taken into consideration. The adequate number of calories for the athlete’s sporting endeavour, plus the appropriate ratios between the macronutrients (protein, fat and carbohydrates) is very important. Specific performance nutrition also considers the timings of food and drinks before, during and after exercise (20), along with sufficient micronutrient intake (vitamins and minerals). The American College of Sports Medicine, American Dietetic Association, and Dieticians of Canada came up with a Joint Position Statement that provides a good understanding of this approach (21). The document focuses on: overall caloric needs of the athlete, carbohydrates to support blood sugar and replace glycogen stores, proteins for growth and repair of muscle, fat as a fuel, hydration for performance, and the micronutrient requirements of the diet.

The exact guidelines of these, and other position statements, are useful for an athlete or a nutritional advisor as a starting point to support nutrient needs during training and competitive situations, but the needs of each individual vary enormously, meaning that a personalised approach is vital. For example, there has been a lot of debate in the sports nutrition literature about the protein needs of sportspeople, especially more trained athletes. Some scientists (and coaches) are gaining athletic success with much higher protein consumption than is commonly accepted, whereas, on the other hand, there are athletes who are competing on a vegan diet, which as a nutrition strategy, makes it extremely difficult to reach even the most conservative protein intakes. So, what will work for one person will not necessarily work for another; hence personalisation is key.

Third layer: This layer focusses on the ‘health’ of the athlete. Good scientific practice begins by creating a hypothesis before trying to prove it. The underpinning hypothesis of integrative sport and exercise nutrition is that body system health is a prerequisite to optimum athletic performance.

Consider what would happen if an active individual consumes foods that provide the recommended gram values of macronutrients, but which initiate gastrointestinal distress and musculoskeletal inflammation. Carbohydrate quality is an example of health awareness in this context: a bagel made from bleached flour, with added conditioners, might possess the same carbohydrate gram value as a bowl of organic brown rice, but the effect of each on an athlete’s gut can be devastatingly different in a competitive situation.

With compromised health, such as gastrointestinal distress during training sessions, repeated bouts of illness during the high volume part of offseason training, or the lengthy frustration of an overuse injury due to poor management of inflammatory cytokines, an athlete is not going to perform at their potential. Integrative nutrition for health means just that – to eat in a way that nourishes each body system in a way that improves its function, and therefore health. Dietary quality is central to this point because food should be seen for more than just its energy-containing properties; food has the power to nourish the health of each body system, and as it does it provides a strong basis for physical performance.

Base layer: Seasonal organic nature-made food sounds incredibly obvious as a nutrition aim, but sports nutrition practice has become so clouded by quantitative norms, that unfortunately health is not generally supported as a primary aim. But where our athletes direct their attention can be relatively easy to change. If, for example, our sporty clients mindfully trade in where they buy their vegetables, they can upscale the nutritional density in their diets, decrease their exposure to the toxic chemicals utilised in conventional farming, and improve many indices of health (22-24). Not only is this potentially good for them, including their health and performance, but it is good for the environment too. As proposed by Simone do Carmo in her article Can Athletes Eat to Podium and Help Save the Planet?: “engaging athletes in environmental sustainability and getting them to share their experiences can only have a positive downstream effect on the wider society to boost athlete health and help save the planet.”

Evidence based practice

In order to progress as practitioners in the efficacy of the way we work, it is essential to practice from a strong base of evidence based practice. This does not mean, as the phrase could suggest, that we intervene only with practices that have a strong research base. Rather, in the words of Johnston et al., “The practice of evidence-based nutrition involves using the best available nutrition evidence, together with clinical experience, to conscientiously work with patients’ values and preferences to help them prevent, resolve, or cope with problems related to their physical, mental, and social health (25).” As professionals of health and human performance we learn from science, our own experiences, and very importantly, our clients.

As shown in Figure 3, this thinking has been represented visually by Jones (26) who suggested that optimal health outcomes come from an integration of research evidence, clinical practice (experience), and the patient’s story.

Figure 3 – Integration of science with clinical practice (26)

Concluding remarks

My key objective for writing this article is to encourage sport, exercise and nutrition professionals, whether still students of this subject, or seasoned practitioners, to embrace the complexity and individuality of an exercising person. This approach ultimately builds practice potential beyond the prevailing macronutrient-focussed paradigm that has been carried forward by many scholars in this field to date.

Our mind-body systems (including gastrointestinal, immune, detoxification, musculoskeletal, neuroendocrine, bioenergetic, and mental-emotional) integrate with one another fluently to the degree that imbalance in one area likely influences another. The pressure of heavy training loads, often alongside significant life stresses, can throw the clients’ physiology out of balance, rendering them susceptible to health maladies, and diminished physical performance.

There are many examples of talented sports people with unhealthy eating patterns – now and in the past. Integrative and personalised nutrition is not therefore a magic bullet that will rapidly propel healthy eaters to sporting stardom. However, practitioners trained to support integrative body system health through nutrition and lifestyle strategies are well positioned to support the robust health and performance requirements of active individuals in a personalised way. If, over time, an active body is receiving deep nourishment that falls in line with their personal physiological needs, this person stands a better chance of optimally adapting to training sessions, encountering fewer injuries and bouts of illness during their career, and ultimately experiencing longevity within their chosen pursuit. This notion applies as much to the professional sportsperson as it does to the busy executive who is training for a large sports challenge within the confines of extreme time pressures.